Lab Report #1 Biology 721b3c

Introduction Cells are the fundamental unit of all life. These fundamental units can be broken into two classes of organisms called Prokaryotes and Eukaryotes (Reece et al., 2014). Each of these two classifications of cells will have different size and functions allocated to them. In order to further understand the functions of these cells we must study them in the lab. Prokaryotes are single celled, simple organisms without a nucleus whereas Eukaryotes are more complex organisms consisting of a nucleus and a cell membrane. Eukaryotes can be multicellular as well as single cellular (Recce et al., 2014). However these two groups of organisms are microscopic and are not visible to the human eye therefor in order to accurately understand their unique differences we observe them through light microscopes. In this experiment we examined the size, structure, and motion of organelles with in the cell. We examined bacteria and yeasts cells, Elodea cells, human epithelial cells as well as ciliates and flagellates using the Leica DME microscope in order to further our understanding of the unique functions of Prokaryotic and Eukaryotic cells. Methods In part one of the experiment we observed the bacteria and yeast culture by removing a slide from the alcohol jar using forceps using a Kim wipe to dry it as to not leave fibers on the slip. Then after swirling the culture one drop was placed in the center of the slide. After culture was applied to the slip a drop of methylene blue stain is added to the culture on the slide. A cover slip was applied by sliding it at a 45 degree angle until the cover slip s the liquid and allow it to drop (Biology

Department, 2015). The slide was then carefully placed on the stage of the microscope and is held securely be the stage clips. Using the 10x objective lens the stage was adjusted so that the slide and lens were about 6mm apart. After adjusting stage to the working distance the 40x lens was used by simply switching the lens and focusing with the fine focus knob. During this step yeast cell start to become visible however bacteria are still too small to be seen (Biology Department, 2015). In order to view the bacteria cell the oil immersion lens is used by placing a drop of oil on top of the coverslip and allowing the lens to sit in the oil. Finally the micrometer eyepiece is used to measure the size of each specimen. Recorded observations. In part two with a clean and dry slide one drop of distilled water was placed in the centre of the slide. One leaf was added to the slide making sure as to not fold it upon itself with a coverslip applied with proper procedure. Once within working distance of the 10x lens begin to use the stage controls to find the area of the leaf that looks to be the central vascular tissue (Biology Department, 2015). Observed the cell through both the 40x and 100x lens for a better visual description of the cell. Recorded observations. In part three a slide that was both clean and dry was used to place a drop of methylene blue stain in the centre. Then using toothpick to scrape off the epithelial cells on the inside of the cheek which were then placed into the stain. Discarded toothpick applied a coverslip using proper procedure. Using the 10x adjust the stage until within optimal working distance (6mm). Then viewed the specimen using the 40x lens. Recorded observations.

In part four a clean slide is used to place a drop of Ciliate culture of which the name was recorded as well as a drop of Protoslo to slow the cell down (Biology Department, 2015). Applied a cover slip using proper procedure. The 10x lens was then used to locate the Ciliate cells. Recorded observations. The same steps are then repeated for Flagellates .Recorded observations.

References 1. Biology Department. 2015. First Year Biology 1003/1103 Laboratory Manual Fall Term 2015. Carleton

University Press, Ottawa, ON.

2. Reece, J.B., L.A. Urry, M.L Cain, C.A. Wasserman, P.V. Minorsky, R.B. Jackson, F. Rawle, D. Durnfird, C.Moyes, S Walde & K. Wilson. 2014. Campbell Biology: Canadian edition. Pearson Canada Inc., Toronto, ON.